1. Field of the Invention
The present invention relates generally to the field of electrical outlets and more particularly to devices which cover an outlet to prevent unintentional contact with the electrical supply voltage provided by the outlet and therefore prevent accidental electrocution.
2. Description of the Prior Art
The field of devices which cover an electrical receptacle to prevent accidental contact with the electrical supply voltage has been studied extensively and a variety of approaches have been developed. This field is important due to the fact that in most installations an electrical receptacle is located such that the young, infants and toddlers, can easily access the electrical voltage provided by the outlets of the receptacle. Even though the need to protect these persons from the threat of accidental electrocution is clearly defined, the approaches to the solution of the problem vary greatly.
One example is disclosed in U.S. Pat. No. 4,915,638 issued to Domian. This device consists of a hinged cover which in a closed position totally encloses the face of the electrical outlet. The cover is held in the closed position by a childproof lock. The lock is a single flexible tab which engages a slot in the mounting plate of the invention to lock the cover in a closed position. The cover has slots in the bottom edge of sufficient dimension to allow for the passage of electrical cords. Even when the cover is in a closed or locked position a metallic or other electrically conductive instrument could be passed through the cord slots in such a way as to make contact with the electrical supply voltage. This is especially true when a cord is not passing through one or more of the slots.
Another example similar in approach to the Domian Patent is disclosed in U.S. Pat. No. 4,740,655 issued to Ford. This device again consists of a hinged cover which totally encloses the face of the electrical outlet when the cover is in a closed position. Various hinge and childproof lock arrangements are disclosed which allow a person of sufficient knowledge and dexterity to unlock and open the cover which is hinged from one side. Openings in the cover allow for the passage of electrical cords. As in Domian, no provision is made for blocking access to the electrical supply voltage by objects inserted through the passages for the electrical cord or cords.
In a similar manner, U.S. Pat. No. 4,851,612 issued to Peckham; U.S. Pat. No. 5,045,640 issued to Riceman; U.S. Pat. No. 5,195,901 issued to Correnti; U.S. Pat. No. 5.218,169 issued to Riceman; U.S. Pat. No. 5,252,083 issued to Correnti; U.S. Pat. No. 5,264,662 issued to Kennedy, U.S. Pat. No. 5,362,924 issued to Correnti; U.S. Pat. No. 5,382,755 issued to Correnti; U.S. Pat. No. 5,389,740 issued to Austin; and U.S. Pat. No. 5,556,289 issued to Holbrook all disclose devices which include a baseplate which is attached to the electrical outlet and a separate hinged cover which completely encloses the electrical outlet when the cover is in a closed and locked position. In each of the above patents, provision is made for a childproof lock to prevent a person not having the requisite knowledge and manual dexterity from opening the cover. The patents listed above allow for passage of an electrical cord or cords through the cover but do not prevent an electrically conductive object inserted through the passage for the electrical cord from making contact with the electrical supply voltage. Therefore the possibility of accidental electrocution still exists even with the cover in a closed position.
U.S. Pat. No. 5,527,993 issued to Shotey, et al. discloses a device which includes a baseplate and separate hinged cover as in the above patents. The device also includes a rubber boot or rubber flaps on the inside of the cover to make the device weatherproof. The electrical safety aspects of this device or childproof latch are not claimed. It appears, however, that the protective boot or flaps would in addition to making the device weather proof also prevent an electrically conductive object from being inserted in such a way as to make contact with the electrical supply voltage. The device consists of multiple pieces and is of a complexity which would make it difficult to produce economically.
Finally, U.S. Pat. No. 4,993,963 issued to Pedigo discloses a hinged cover and baseplate joined as a single unit by a xe2x80x9clivingxe2x80x9d hinge. The slot through the cover of the device for the passage of electrical cords is large and extends from the edge of one side of the cover portion to a point at the midpoint of the front of the cover. The arrangement of the large slot in the device provides an even greater opportunity for a young person to insert an electrically conductive object through the cover and into contact with the electrical supply voltage and therefore creates an even greater possibility of accidental electrocution.
Thus, a variety of safety devices for electrical receptacles are known. All of the referenced devices employ a removable or hinged cover to completely enclose the electrical cords and plugs which are connected to the outlets of the receptacle. However, none of the above-described references disclose a simple one-piece safety enclosure for installation on an electrical receptacle which completely protects a young person from accidental electrocution.
Accordingly, it would be desirable to develop an electrical safety outlet which completely protects a young person from accidental electrocution. At the same time the electrical safety outlet must be a simple, one-piece design for ease of manufacture.
In view of the foregoing disadvantages inherent in the known types of safety covers or enclosures for electrical receptacles, the present invention makes available complete protection from electrocution at an affordable price. As will be seen from the following description, it is the goal of the present invention to provide all of the protections afforded by the prior art with none of the disadvantages while at the same time reducing complexity.
To achieve this goal, the present invention comprises a one-piece structure molded or formed from a fire-retardant electrical insulation material and having a box-shaped cover joined at the top edge to a rigid base plate by a flexible hinge. The flexible hinge is formed by reducing the cross-section of the material in the region of the hinge. The flexible hinge allows the cover to rotate approximately 90xc2x0 from a closed position wherein the cover engages the rigid base to an open position which allows electrical plugs to be inserted into the sockets of the electrical receptacle.
In use, the present invention is installed on an electrical receptacle by removing the standard cover and replacing it with the invention. The invention provides a mounting hole which is precisely aligned such that a standard mounting screw inserted through said mounting hole and tightened into the receptacle completes the installation. The cover of the invention is maintained in an open position during the installation process and for installation of plugs and power cords into the electrical outlets of the receptacle. Rectangular notches in the opposing side walls of the cover provide passageways for electrical cords when the cover is in a closed position. Once all plugs have been inserted into the outlets of the electrical receptacle the power cords attached to the plugs are routed through the notches in the cover and the cover is closed. Three stiff but flexible tabs formed as a part of the cover extend outward from the two opposing walls and the bottom wall of the cover and engage corresponding slots in the rigid base when the cover is closed. Baffles extending outwardly from and perpendicular to the plane of the rigid base allow for flexible electrical power cords to pass through the notches in the cover. Said baffles are located in such a manner that direct access by a rigid object to the interior region of the cover is prevented. The cover is maintained in a locked and closed position by small ridges formed on the tips of said tabs and extending outwardly away from the interior region of the cover and in a plane perpendicular to the plane of said tabs. When the cover is closed, the tabs pass through corresponding slots located in the rigid base and are forced inward toward the interior region of the cover as the said ridges at the tip of said tabs engage the wall of said slots. When the cover reaches the closed position the tabs snap outward away from the interior region of the cover as said ridges located at the tips of said tabs snap into recesses provided in the rigid base. To open the cover it is necessary to apply pressure inwardly toward the interior region of the cover on all three of said tabs simultaneously to allow said ridges to clear the walls of the slots in the rigid base. The size of the cover and the dexterity required to apply pressure to all three of the tabs simultaneously effectively prevents the cover from being opened by an infant or young child. Further, even if one or more of said tabs are not positioned properly for said ridges at the tips of said tabs to lock the cover in a closed position, the cover can only be opened by the proper application of force to the appropriate tabs to release the cover. In this way, a fail-safe feature is afforded by the present invention.
Said cover includes truncated trapezoidal protrusions aligned with the outlets of the electrical receptacle to provide clearance for the plugs and electrical cords. In this way the depth of the side walls of the cover is reduced for a better visual appearance and a reduction in the volume of material required to form the invention. For industrial and commercial applications, the protrusions and the depth of side walls can be increased to accommodate the larger plugs and electrical cords utilized in these applications.
In another embodiment of the present invention, a weather proof feature is provided by placing a gasket of a compressible and electrical insulator material between narrow plane surfaces formed in the corresponding mating edges of the cover and rigid base.